US2208522A - Lighting sewing machines and the like - Google Patents

Description

y 1940. P. A. CULLMAN LIGHTING SEWING MACHINES AND THE LIKE Filed Sept. 3, 1936 4 Sheets-Sheet l INVENTOR fifiaall/zaa/z ATTORNEY July 16, 1940. P. A. CULLMAN LIGHTING SEWING MACHINES AND THE LIKE Filed Sept. 3, 1936 4 Sheets-Sheet 2 a m w RNVENTOR VfQW 4&CZZ7IZCZIC ATORNEY July 16, 1940. P, A, CULLMAN 2,208,522

LIGHTING SEWING MACHINES AND THE LIKE Filed Sept. 3, 1936 4 Sheets-Sheet 5 'I II/[Z g gBY ATTORNEY y 1940- P. A. CULLMAN 2,208,522

LIGHTING SEWING MACHINES AND THE LIKE Filed Sept. 3, 1956 4 Sheets-Sheet 4 N N [A 10/ 5 I05 104 :5 If 102; E/ 1 m5 H H l i zw K78 m ugh b u! H i g (A III K I II a 1% W E14 f ATTORNEY Patented July 16, 1940 PATENT OFFICE azoaszz monme sswmo moms AND 'rnr:

rmup A. Cullman, New York, N. Y., asslgnor, by

meme assignments, to Lenslite notation of Florida 00. Inc., a cor- Application September 3, 1936, Serial No. 99,302 g 26 Claims. (01. 240-214) This invention relates to lenses and light projectors, and more particularly to theircombination with and adaption to sewing machines.

The operation of sewing machines requires constant application to close work. At night under average or poor illumination the worker is subjected to much physical'and eye strain with a resulting lessening of eiiiciency and health. To eliminate this condition by providing means for correctly illuminating the work tables of sewing machines is the principal purpose 01 this invention.

Another object of the invention is to provide a refractor suitable for properly illuminating the table of a sewing machine.

A further purpose of the invention lies in the production of a refractor which when placed on or within a sewing machine will project a beam having its most intense portion at the needle or in a small area about the needle on the work A further purpose of the invention is to illuminate the sewing machine table without glare in the eyes of the workman.

Another object of the invention lies in the provision of different lenses, reflectors and light projectors whichwil! be suitable for mounting on different types of sewing machines.

Still another object of the invention is to provide light projectors adjustable in position and efi'lcient in operation for use withsewing machines.

Another purpose of the invention is to provide refractors and light projectors for use with sew-' ing machines harmonizing with the appearance of the machines and adding to their attractiveness.

A further purpose of the invention is to provide refractors and projectors which will cheaply render adequate illumination for close work on sewing machines.

To aid a fuller understanding of the invention the accompanying drawings are included in which Fig. 1 is perspective view of a baby model sewing machine having mounted on its front side a refractor embodying the invention. 1

Fig. 2 is a bottom view of the refractor alone. Fig. 3 is a vertical central section of the re- 5 iractor taken on line 20-40 of Fig. 2.

Fig. 4 is a vertical section of the refractor with hood added taken on line 2l-2l of Fig. 3.

Fig. 5 is a diagrammatic representation showing the refractor in section and illustrating the paths of light rays from a source before and after refraction.

Fig. 6 is a perspective view of a portion of a sewing machine on which is mounted a light projector adjustable in directions of light output.

Fig. 7 is a vertical central section of another lens and reflector embodying the invention showing directions taken by light rays from a source before and after refraction and reflection.

Fig. 8 is a diagrammatic representation of the beam pattern on the table produced by the projector in Fig. 7.

Fig. 9 is a front elevation of still another lens embodying the invention.

Fig. .10 is a horizontal sectional view of the lens taken on line 22-22 of Fig. 9.

Fig. 11 is a section of the lens taken on line 2323 of Fig. 9 including a reflector and housing with directions of light rays from a source before and after refraction.

Fig. 12 is a diagrammatic representative of a beam pattern on the table produced by theprojector in Fig. 11.

Fig. 13 is a vertical central section of still another lens embodying the invention drawn to scale half size with dimensions shown in inches.

Fig. 14 is a front elevation of the lens shown in Fig. 13 enlarged.

Fig. 15 is a vertical section of the lens taken on line 123-123 of Fig. 14 and enlarged.

Fig. 16 is a vertical diagrammatic central sectional representation of the lens with light source and reflector added. 1

Fig. 17 is an enlarged vertical central section of the projector in Fig. 16 showing the paths of light rays from a source before and after refraction.-

- Fig. 18 is a diagrammatic representation of a beam pattern on the table produced by the projector in Fig. 16.

Fig. 19 is a section of a flat lens which may be used in place of the refractor shown in Fig. 3.

Referring more particularly to the drawings Fig; 1 portrays a refractor 24 embodying the invention mounted on the front side of a small sewing machine 25. Surmounting the refractor is a semi-cylindrical hood 26 at the, rear end of which is a cylindrical projection 21 which serves to house the socket for an incandescent lamp.

The details of the refractor construction are clearly shown in Figs. 2, 3, and 4. In designing refractive angles.

the refractor an incandescent fllament source of light is located at the point 26 in Fig. 3. From a point 26 located on the horizontal 1ine'HI-I containing the light source arcs 4| and 42 are drawn with radii RI vand R2 respectively. These arcs are merged into the horizontal straight lines 4| and 42 which form the inner and outer sides of the refractor element of revolution. On the outside element 42 straight side prisms 66-46 inclusive are formed each having the same width 46 but each differing from the others in height andre-.

fractive angles. Straight line prisms 36-46 inelusive and 56-52 inclusive are formed 'on the inner side 4| of the refractor element 24. All of these prisms are identical in width 43 but only prisms 46, 56, 5|, and 52 are alike in height and Prisms 36, 61, and 66 each differ from the others in these respects.

The element of the refractor 24 formed as above described is then revolved approximately vertically about the horizontal axis H-H, and approximately 45 on each side of the vertical V-V as shown in Fig. 4. The shape of the refractor is then changed by the formation of a flat vertical side 44 extending approximately to the horizontal plane containing the axis of revolution. The rear portion of one side is continued still higher to form flat vertical projections 45 with the slot 46 between them, Fig. 3.

Upon the forward spherical end of the refractor 24 thus formed are placed vertical flutes 53-51 inclusive shown in Fig. 2. The center flute 53 has the largest radius. Flutes 54 and 56 have equal and smaller radii and flutes 55 and 51 have equal and still smaller radii.

The complete refractor is essentially a semicylindrical one open at the rear end 41 Fig. 5 and closed at the front end by a-semi-spherical section containing external vertical flutes. External straight prismatic zones of refraction are formed on the under portion perpendicular to the flutes and internal straight prismatic zones of refraction are formed at the rear end of the refractor.

In order to mount the refractor on a sewing machine a metal hood 26 Fig. 4 having the same general shape as the refractor is flrst amxed to the machine by means of the screw 46. Referring to Figs. 1 and 4 a rectangular, spring metal plate 56 is fastened to the hood 26 by means of rivets 46. An incandescent tubular lamp 66 is inserted in the socket 21 at the rear end of the hood 26. The refractor is'then slid up into place the slot 46, Fig. 3 providing room for the screw 46 and the spring clip 56 fitting snugly about and under the flange 56 on the refractor holding it flrmly in place. The horizontal pressure produced by the clip 66, on the projections 45, Fig. 3 prevents any displacement of the refractor without flrst releasing the clip 56.

Fig. 5 illustrates the action of the refractor in controlling light rays whose paths are shown dotted. It will be seen that internal prisms 5| and 52 retract the incident rays traveling downwardly and to the right in such manner that they emerge at angles closer to the vertical although still moving slightly to the right. Prisms 56, 46, and 36 throw the emerged rays successively further and further to the left. Prisms 36-36 inclusive converge thelight rays toward the position of the needle 62 on the sewing table 6|. The spherical fluted portion of the refractor projects light rays to the left of the needle, the flutes spreading them toward and away from the worker. The retracting zones control and form a beam approximately 90 of solid angle in directions to and from the vertical plane containing the axis of the refractor. Thus the working table is illuminated fully by a beam having its most intense portion in a rectangular area about the needle where it is most needed. None of the light is above the horizontal and therefore cannot create glare in the workmans eyes which are above the refractor. The flat lens shown in Fig. 19 may be used in place of the refractor 24.

The refractor with minor changes in design and size may be shifted in position, placed in front or behind, on larger or smaller machines and may even be incorporated in the lower part of the sewing machine arm 25 and still accomplish its purpose of producing a better light distribution on the work table. The appearance of the refractor as above described is neat and attractive, completely harmonizing and adding to the appearance of the sewing machine.

Another means of satisfactorily lighting the machine table is to mount a light projector entirely separate from the machine proper. This can be done for example as shown in Fig. 6. Here a light projector consisting of a paraboloidal housing 63 and a lens 64 are mounted on the end of a tubular arm 65 at the top end of which is located a universal ball andsocket' joint 66 supported in the arm 61 which is in turn supported on the sewing machine table 6|. The universal joint 66 allows adjustment of the light beam in any direction within approximately spherical degrees. With this arrangement the workman can adjust the light beam as best suited to his 25 if desired or may be supported in any other convenient manner.

One embodiment of the projector used above is shown in Fig. 7 in vertical central section. Here thelens 64 consists of concentric inner and outer spherical surfaces 13 and 14 respectively.

Formed on the inner surface are the annular rei'racting zones 66, 66, 1| and 12 and the bulls-eye 16. The rear apices of said retracting zones fall in a spherical surface concentric with those of .the inner and outer faces of the lens. Prism 12 is straight in section but prisms 66, 66, and 1| have curved incident sides formed by radii successively shorter from top to bottom. The centers for radii R66, R66, and the radius of the bull's-eye R16 lie on the axis of revolution of the lens section H-H while the center for the radius of curvature of prism 1|, R1| lies below the axis of revolution. The substantially paraboloidal housing 66 retaining the lens is plated and polished or otherwise provided with an inner surface of high reflecting power. The resulting paths of rays-in accordance with the well known laws of reflection and refraction are deputed in Fig. '1. Rays from the source 26 reflected by the housing are shown dotted while those which are directly received on the lens without previous reflection are shown in full line. These latter it will be noticed emerge from the lens converging slightly toward the axis of revolution HH when refracted by the upper portion of the lens. Those refracted by the lower portion of thelens converge much more rapidly toward the axis of revolution resulting in an asymmetric beam. The substantially parallel rays, striking the lens from the reflector housing, are, as shown, re-

angles, and cross the axis of revolution diverging rapidly.

When the projector is suspended above the table at a suitable height the beam pattern on the table GI isas represented in Fig. 8. Here again 02 represents the position of the needle. The intense portion of the beam consisting of rays which are refracted only surrounds the needle 62.. Of this portion the part 15 comes from the lower portion of the lens and is behind the needle. The area 10 is intensely lighted by refracted rays only from the upper portion of the lens and is between the needle and the workman. Surrounding the intense portion of the beam is the lower intensity area 'II produced by rays both reflected and refracted which supply general illumination on the table. This beam pattern is ideal in distribution having the intense light exactly wheredesired about one-third back of the needle and two-thirds ahead of it and as previously explained the workman can adjust the position of the projector to suit his requirementsand taste.

The lens above described is approximately three inches in diameter. The invention, however, is not limited to this particular size or shape.

The paraboloidal reflector can be changed in shape without materially altering the general illumination obtained. A portion of it may even be made diffusely rather than specularly reflecting without sacrificing and perhaps bettering the characteristics of the beam.

- Another lens I8 embodying the invention which may be substituted in the projector for the one I above described is shown in Figs. 9, 10, and 11. This lens is round having a flat rear surface upon which are formed vertical flutes 95, Fig. 10for the purpose of changing the round beam pattern into a rectangular one. Upon the outer surface of the lens are formed horizontal straight prismatic retracting zones 8I-92 inclusive. In the center of the outer surface of the lens 18 are formed annular prismatic zones 93 and 94 differing from each other in refractive angles. The corresponding horizontal prisms of the upper half of the lens are similar to those of the lower half thus giving a symmetrical beam but each prism of one portion of the lens differs from every other of the same portion in refractive angle. Thus prism 86 differs from each of prisms 8|, 82, 83, 84, and 85, but is exactly the same as prism 92 in the lower half of the lens. The prisms increase in refractive power the further they lie from the center of the lens. The innersides of all prisms are parallel to the paths of rays through the lens in their respective positions. This features causes all of the rays from the source proceeding directly to the lensto be eificienctly refracted in the desired directions without production of any stray light refracted from the inner sides of the prisms, I

In Fig. 11 the lens is assembled in a cylindrical housing 96 flanged at one opening to contain it. A wire retaining ring 91 holds the lens in place. A spherical reflector 95 having its center at the focus 28 of the lens is also used. The inner forward portion of the housing 90 is polished to form a reflecting surface and the whole unit mounted in similar manner to the projector shown in Fig. 6. In Fig. 11 the solid lines represent paths of rays directly striking lens from the source 28 which is placed at the focus of the lens and the rays reflected by the spherical reflector. These rays emerge concentrated and parallel and form the intense portion 80 of the beam pattern shown in Fig. 12. .Here 62 again represents the position of the needle on the sew-' ing table GI. The. dotted lines Fig. 11 represent the paths of raysstriking the housing which are reflected and refracted to emerge from the lensv t widely diverging angles to form the low intenity portion of the beam pattern 99 in Fig. 12..

If the housing is made diffuse reflecting, a-better beam is obtained. The oval shape of the beam is occasioned by the vertical flutes 95 previously mentioned. I I

Still another lens embodying the invention and which may be substituted for the lenses above described in a separate projector is shown in Figs. 13-17 inclusive. Referring to Fig. 17 more particularly, the lens I is shown in -section. The mechanics of its design consists in choosing a rectangular vertical section I 00 and forming at its ends the rearwardly projecting flanges IOI. A circular arc I02 is drawn on the outside with radius RI2 and center on the hori zontal H-H containing the focus 28. Two prisms 7 I03 and I04 are drawn on the innerside at its top. The incident sides of these slope 2 away from the horizontal to-allow withdrawal of the manufacturing plunger. These prisms are made total internal reflecting by forming their upper sides with long radii RI3 and RI4 having centers below and to the right of the lens. Two similar prisms H0 and I09 are constructed on the bottom of the inner surface these having reflecting sides formed by still longer radii R20 and RI 9 above and to the right of the lens. Below prism I04 is constructed the refracting prism I05 having a short radius with its center on H-H. A

. similar prism I08 is formed below having a slightly longer radius but with center on H H. Refracting zones I06 and I0! are then formed by drawing arcs with unequal radii RIG and RI I having different centers in HH. RI'I be vthe outside face of the lens as shown in Figs. 14

and 15. Flute H3 is the only simple radial flute and is formed on the bull's-eye I02 with radius of curvature R23. Flutes I I2 and I I4 are transitions between flutes and prisms having sections which are straight lines merging into arcs with radii R22 and R24 respectively. Of these two the latter is the longer being on the upper portion of the lens. The straight portion of the external surface contains five equal flutes III which are also partially prismatic. Their radial surfaces are formed with radius R2I.

The functions of these prisms is to spread the beam vertically. In accomplishing this purpose the prismatic portions of the flutes tend to converge diverging rays toward paths substantially parallel with the horizontal H--I-I. The radial portions of the flutes diverge the light vertically up and down, flute II2 causing slightly more divergence than flute I I4. of the flutes tends to even the intensity of the beam and eliminate prism striations.

The lens I00 may be assembled in a projector as shown in Fig. 16. The housing here consists of a semi-spherical upper portion II5 formed by the revolution 180 about HH of an are having radius R30 and center I30 below H-H and The diffusing nature is turned at the other end to house the socket for lamp 80. v

The dotted linw in Fig. 17 illustrate the paths of light rays before and after refraction by lens I00. Internal reflecting prisms I03, I00, I09, II0, it will be noticed-produce rays diverging from HH diverging at slightly greater angles from the lower portion of the lens than from the upper. Refracting zones I05 and I08 take direct light from the source 28 and cause it to emerge in paths practically parallel ,with the axis of revolution HH, while rays controlled by zones I01 and I08 emerge at small divergent angles with HH. The net result is to produce a concentrated beam which is asymmetric tending to wider spread and less intensity in the portion produced by the lower half of the lens. The inner sides H5. and III of the housing being plated and polished to form a reflecting surface produce a general widespread illumination of low intenuse on larger sewing machines.

of the beam." Light from upper portion I I5 is reflected downwardly undergoes refraction and emerges from the lens downwardly at large diverging angles with HH. Similarly light reflected by the lower portion of the housing I" diverges upwardly at large angles.

The resulting beam pattern is clearly shown in Fig. 18 where again IiI represents the sewing table and 62 the position of the needle. It will be noticed that when the projector is placed as in Fig. 6 and adjusted the very intense smaller portion of the beam II! from the upper half of the lens surrounds the needle. lower intensity and larger portion of the beam from the lower half of the lens I20 is in front of the needle on the work about to undergo the sewing operation while the low intensity general illumination I2l proceeds from the reflector. It is the flutes previously mentioned which produce the elongated characteristics of the beam pattern. Should it be chosen to leave them off, the pattern would consist of two semi-circles of high intensity light of different radii surrounded by two semi-circles of low intensity light of different radii. However, the elongated oval shaped beam is more desirable as explained in connec--' tion with the projector described in Fig. 'I.

Should it be desired to make both halves of the lens alike, the resulting beam pattern will of course be symmetrical.

While a detailed portrayal has been given of some of the forms the invention may take not only in its optical characteristics but also its mechanical features, it is not intended to limit the invention to the above description. The; efflciency in quantity and quality of illumination obtained, and the beauty and harmony of appearance of the small projectors described will not be sacrificed in the design of larger ones for I Changes in the number of prisms placed on the refractor or changes in refractive angles, curvatures and centers of curvatures of prisms and lens to produce a similar type of beam when projectors are changed in mounting heights or otherwise changed in position may be made without de- The slightly I claim: I I

1. In combination with a sewing machine, a

light projector mounted thereon, including an' electricallyenergized light source within said projector and a lens, said lens having light contr'ol'means to direct a restricted and concentrated beamof light downwardly upon the needle working position of said machine, and other means to allow light to pass therethrough to provide light of lesser intensity around the area illuminated by the concentrated beam;

2. In combination with asewing machine, a light projector mounted thereon, including an electrically energized light source within said projector and a lens, said lens having light control means to direct a converging concentrated beam of light'downwardly upon the needle working position of said machine, and other portions to allow light to pass therethrough to provide light of lesser intensity around the first mentioned beam.

3. In combination with a sewing machine, a light projector mounted thereon, including an electrically energized light source within said projector and a lens, said lens having light control means to direct a beam of light, the cross section of which is elongated in a direction substantially in line with the work path of the machine, upon the needle working position of said machine, and other portions to allow light to pass therethrough to provide light of lesser intensity around the first mentioned beam.

4. In a sewing machine, means for illuminating that area of the machine including and surrounding the needle; said means including a light source and refractor, said refractor having a light control zone so constructed as to concentrate a beam of light of greater intensity on said area and other portions so constructed as to produce a divergent beam of lesser intensity to illuminate a relatively larger area about the first mentioned area.

5. The combination with a sewing machine, of a prismatic refractor mounted on the machine, a light source therefor, the refractor including means to divide light rays passed therethrough, a

centrally located section of said means refracting illuminate parts surrounding said part of the machine. I

6. In a sewing 'machine, a plane work table surrounding a minor area for mechanical operation upon material guided thereto, means for illuminating said minor area and a surrounding area on said work-table, the minor area receiving the most intense illumination from said means, said illuminating means being mounted above said work-table and including a lens, a light source in the rear of said lens and light control zones so formed on said lens that light from said source is partially concentrated at said minor area along the path of travel of work on said machine, while light passing through the remainder of the lens is spread over said surrounding area.

7. A controllable mechanism including a plane work-surface surrounding a minor area for mechanical operation upon material guided thereto, means for illuminating said minor area and a surrounding area on said work-surface,

said illuminating means being mounted above said work-surface and including a lens, a light source behind said lens, prismatic surfaces formed in said lens and so oriented relative to each other as to direct a concentrated light beam and to elongate said light beam substantially in the direction of travel of material to be worked upon and for producing a light of lesser intensity surrounding said elongated area. v

8. The combination with a horizontally disposed work surface across which work is to be fed, of a light source positioned above said surface, a reflector enclosing the upper side of said light source and a prismatic refractor enclosing the under side of the light source and having light control zones to direct its rays downwardly within an area substantially less than that of the work surface, one of said zones acting to project a concentrated light from said source upon a relatively small area of the illuminated portion of the surface, said area being elongated substantially in line with the path of travel of the work, and other of said zones acting to illuminate with a lesser intensity a relatively larger area of the illuminated portion of the surface about said concentrated beam.

9. In combination, a controllable mechanism having a definite working station and means for projecting an intense light of relatively small area upon said working station and a light of relatively less intensity but covering a sub stantially greater area, immediately adjacent said working station and surrounding said area of intense light, both of said light areas being elongated in the direction of and substantially in line with the path of travel of work to be fed to said working station.

10. In a machine for working upon material fed thereto, a definite working station across which work is to be fed, means for projecting an intense light covering a relatively small area at said working station, the intense light being divided into a plurality of immediately adjacent zones of varying intensities; and a light beam of relatively less intensity bounding the intensity illuminated area.

11. A manually controllable mechanism including a plane work-table surrounding a minor area of mechanical operation upon material manually guided thereto, means for illuminating said minor area and a surrounding area on said work-table, the minor area receiving the most intense illumination from said means, said means including a lens so mounted that its axis is parallel to the work-table, a light source mounted on said lens axis, prismatic surfaces formed in the lens transverse of its axis and so oriented relative to each other that light from said source is concentrated about said minor area while light passing the remainder of the lens is spread over said surrounding area.

12. A semi-cylindrical lens with horizontal axis of revolution, open at the top and one end, a spherical portion closing the other end, and internal and external prisms transverse to the axis of revolution formed upon the cylindrical portion.

13. A semi-cylindrical lens with horizontal axis of revolution open at one end and closed at the other by a spherical portion, a reflector, said lens having a plurality of inner and outer prismatic zones transverse to the axis of revolution of diflerent refractive powers so formed on said cylindrical portion that light projected by said reflector from a source passes through said lens for concentration in one zone and diffusion in an adjacent but larger zone.

14. In combination, a sewing machine including a work surface and a light projector mounted in such manner as to effectively illuminate the work surface of said machine with a beam having its highest intensity in the small area surrounding the needle of said sewing machine, said light projector comprising a lens whose axis of revolution is horizontal a plurality of prismatic zones transverse to the axis of revolution formed upon said lens, and a light source within the axis of revolution of said lens.

15. In combination with a light source, a semicylindrical lens with horizontal axis of revolution, open at its top and at one end and having a sub stantially spherical portion at its other end, and internal and external prisms transverse to the axis of revolution formed on the cylindrical portion, said prisms being arranged to form adjacent light control zones, one of said zones being constructed so as to project a concentrated beam of light of maximum intensity from said source and the other of said zones so as to pro ject diffused light of a relatively larger area and lesser intensity about the first mentioned light beam.

16. Alight projector comprising a lens having a semi-cylindrical portion with horizontal axis of revolution, a light source within said axis of revolution, a housing above said lens and having a reflecting surface adapted to direct light from said source downwardly of said lens, and a pinrality of prismatic zones formed on the said lens transverse to said axis' of revolution so that the projected light is concentrated in one zone and diifused in an adjacent but larger zone that is substantially symmetrical with respect to said concentrated zone. 1

17. A light projector comprising a lens having a semi-cylindrical portion with a horizontal axis of revolution, a light source within said axis of revolution, a housing above said lens and having a reflecting surface adapted to direct light from said source downwardly of said lens, and a plurality of prismatic zones formed on said lens transverse to said axis of revolution, so that the projected light forms an asymmetrical field having immediately adjacent zones of concentrated light of different intensities and a symmetrical zone of diffused light of a lesser intensity surrounding said concentrated zones.

18. In a sewing machine, a light projector mounted thereon, said projector comprising an apertured housing with an internal reflecting surface substantially paraboloidal in shape,.a light source at the focus of said reflecting surface, and a lens, closing the aperture of said reflector housing, having a plurality of annular refracting zones, prismatic and toroidal in shape, of different curvatures and centers of curvature, so

formed upon the inside surface of the said lens A as to converge the direct rays from said light source toward the optical axis of said projector, a greater convergence being produced by onehalf of the lens than by the other.

19. In combination: a sewing machine, a light projector mounted above said machine comprising: an apertured housing having an internal reflecting surface, a light source at the focus of said reflecting surface, and a lens closing the aperture of said housing, said lens having a plurality of internal annular refracting zones, of different curvatures and centers of curvature, and so related as to converge the direct rays from the light source toward the position of the needle on the table ot the said sewing machine.-

20. In a sewing machine, a light projector including a lens, said lens having a plurality of retracting zones and a plurality oi total reflecting zones, one portion of said lens diflering from a corresponding portion and each retracting and reflecting zone diflering from the others, said zones being oriented realtively to one another so as to project a concentrated light field about the needle of said machine.

21. In a sewing'machine, a lens having a pin-- rality of retracting zones and a plurality of total reflecting zones, the upper portion of said lens difiering from the lower and each retracting and reflecting zone diiterlng from the others, toroidal surfaces on said zones diitering in curvature and centers of curvature, and a bull's-eye formed upon the outer surface of said lens to produce a more brilliantly illuminated central portion in a light beam from said lens.

22. In a sewing machine, alens having a pluferent-ceriters displaced from the axis of revolu-- tion and whose inner surface is a reflecting surface, a light source in the axis of revolution of said housing, and a lens flanged inwardly closing the aperture of said housing, a plurality of projector mounted above said machine, said light projector comprising a light source and a lens with a plurality of retracting and total reflecting zones oriented in such manner as to project the direct light from said source in an elongated concentrated beam onto the area containing the needle position in the table of said sewing machine.

25. A means for illuminating that area of a sewing machine including and surrounding the needle, consisting in a light source mounted on the machine and a prismatic refractor formed to provide annular retracting zones of different curvatures and different centers of curvature to I direct the light rays from the light source with maximum intensity upon the needle and the area immediately surrounding the needle.

26. Ina light projector, a lens comprising a plurality of retracting zones and a,plurali ty of total reflecting zones, the total reflecting zones being separated by the retracting zones, a light source in the optical axis of said projector, and horizontal flutes formed upon the outer surtace ot the lens, said reflecting and retracting zones and said flutes being oriented in relation to each other so as to converge the direct light from said light source into an oval beam elongated vertically in two elliptical parts in which the part from one portion of said lens has larger minor and major axes than the respective axes of the part from the other portion of the lens.

PHIIIPP A CULLMAN.

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